DSU + kruskal algorithm

#include<bits/stdc++.h>
using namespace std;

const int mx=1e5+123;
int parent[mx],sz[mx];
void make(int v){
    parent[v]=v;
    sz[v]=1;
}

int find(int v){
    if(parent[v]==v)return parent[v];
    return parent[v]=find(parent[v]);
}

void Union(int a,int b){
    a=find(a);
    b=find(b);
    if(a!=b){
        if(sz[a]<sz[b])swap(a,b);
        parent[b]=a;
        sz[a]+=sz[b];
    }
}

int main()
{
    int n,m;cin>>n>>m;
    vector<pair<int,pair<int,int>>>edges;
    for(int i=0;i<m;i++){
        int u,v,wt;
        cin>>u>>v>>wt;
        edges.push_back({wt,{u,v}});
    }
    sort(edges.begin(),edges.end());
    for(int i=1;i<=n;i++)make(i);

    int total_cost=0;
    for(auto &edge:edges){
        int wt=edge.first;
        int u=edge.second.first;
        int v=edge.second.second;

        if(find(u)==find(v))continue;
        Union(u,v);
        total_cost+=wt;
    }
    cout<<total_cost<<endl;

}